Helicopter tail section

Abstract

A vertical stabilizer ( 38 ) is supported by and projects upwardly and rearwardly from the tail portion ( 14 ) of a helicopter fuselage ( 12 ). A tail rotor (TSR) is mounted on the vertical stabilizer ( 38 ) for rotation about a horizontal axis (C). The tail rotor (TSR) is positioned laterally outwardly from one side of the vertical stabilizer ( 38 ). The vertical stabilizer ( 38 ) has an upper end, a lower end and a rear edge recess ( 44 ) located between the upper end and the lower end. The recess ( 44 ) has a laterally convex rear edge ( 50 ). The tail portion ( 14 ) of fuselage ( 12 ) has a rear end extension ( 40 ) that extends rearwardly from the vertical stabilizer ( 38 ) and narrows in width as it extends rearwardly. The rear end extension ( 40 ) of the fuselage ( 12 ) provides vertical area to replace vertical area that was removed by placement of the recess ( 44 ) in the vertical stabilizer ( 38 ). A corner ( 82 ) is formed where the rear edge of the vertical stabilizer ( 50 ) meets the upper edge ( 80 ) of the rear end extension ( 40 ) of the fuselage ( 12 ). The corner ( 82 ) is laterally convex and vertically concave. The upper end of the vertical stabilizer ( 38 ) is wider than the vertical stabilizer is in the region of the rear edge recess ( 44 ). The upper end of the vertical stabilizer ( 38 ) forms a corner ( 84 ) with the rear edge recess ( 44 ). This corner ( 84 ) is laterally convex and vertically concave. The rear end extension ( 40 ) of the tail portion ( 14 ) of the fuselage ( 12 ) has a forward portion including sides that are convex in the vertical direction and a rear end portion that is substantially straight in the vertical direction. The rear end extension ( 40 ) of the tail section ( 14 ) of the fuselage ( 12 ) is both laterally and longitudinally convex.

What claimed is: 
     
       1. A helicopter, comprising:
 a fuselage having a tail portion and a vertical stabilizer supported by and projecting upwardly and rearwardly from the tail portion; 
 a power shaft extending longitudinally through said vertical stabilizer and having an upper end above the vertical stabilizer, 
 a tail rotor mounted on the upper end of the power shaft for rotation about a horizontal axis, said tail rotor being positioned laterally outwardly from one side of the vertical stabilizer; 
 said vertical stabilizer having an upper end, a lower end and a rear edge recess located between the upper end and the lower end, said recess having a laterally convex rear edge; and 
 said tail portion of the fuselage having a rear end extension that extends rearwardly from the vertical stabilizer below said rear edge recess and narrows in width as it extends rearwardly, said rear end extension of the fuselage providing vertical area to replace vertical area removed by the recess in the vertical stabilizer. 
 
     
     
       2. The helicopter of  claim 1 , wherein the rear end extension of the tail portion of the fuselage has a laterally convex upper edge and a laterally convex lower edge. 
     
     
       3. The helicopter of  claim 2 , wherein a corner is formed where the rear edge of the vertical stabilizer meets the upper edge of the rear end extension of the fuselage, and said corner is laterally convex and vertically concave. 
     
     
       4. The helicopter of  claim 1 , wherein the upper end of the vertical stabilizer is wider than the vertical stabilizer is in the region of the rear edge recess, and the upper end of the vertical stabilizer forms a corner with the rear edge recess, said corner being laterally convex and vertically concave. 
     
     
       5. The helicopter of  claim 1 , wherein the rear end extension of the tail portion of the fuselage has a forward position including sides that are convex in the vertical direction and a rear end portion that is substantially straight in the vertical direction. 
     
     
       6. A helicopter, comprising:
 a fuselage having a tail portion and a vertical stabilizer supported by and projecting upwardly and rearwardly from the tail portion; 
 a power shaft extending longitudinally through said vertical stabilizer and having an upper end above the vertical stabilizer; 
 a tail rotor mounted on the upper end of the power shaft for rotation about a horizontal axis, said tail rotor being positioned laterally outwardly from one side of the vertical stabilizer; and 
 said vertical stabilizer having an upper end, a lower end, a laterally convex forward edge, and a rear edge recess located between the upper end and the lower end, said rear edge recess having a laterally convex rear edge. 
 
     
     
       7. The helicopter of  claim 6 , wherein the upper end of the vertical stabilizer is wider than the vertical stabilizer is in the region of the rear edge recess, and the upper end of the vertical stabilizer forms a corner with the rear edge recess, said corner being laterally convex and vertically concave. 
     
     
       8. The helicopter of  claim 6 , wherein said trail portion of the fuselage has a rear end extension that extends rearwardly from the vertical stabilizer and narrows in width as it extends rearwardly. 
     
     
       9. The helicopter of  claim 8 , wherein the rear end extension of the tail portion of the fuselage has a laterally convex upper edge and a laterally convex lower edge. 
     
     
       10. The helicopter of  claim 9 , wherein a corner is formed where the rearedge of the vertical stabilizer meets the upper edge of the rear end extension of the fuselage, and said corner is laterally convex and vertically concave. 
     
     
       11. The helicopter of  claim 8 , wherein the rear end extension of the tail portion of the fuselage has a forward portion that has sides that are convex in the vertical direction and a rear end portion that is substantially straight in the vertical direction.